package com.example.lettcode._20241008;

import java.util.HashSet;
import java.util.Set;

/*
请你判断一个 9 x 9 的数独是否有效。只需要 根据以下规则 ，验证已经填入的数字是否有效即可。
数字 1-9 在每一行只能出现一次。
数字 1-9 在每一列只能出现一次。
数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。（请参考示例图）


注意：
一个有效的数独（部分已被填充）不一定是可解的。
只需要根据以上规则，验证已经填入的数字是否有效即可。
空白格用 '.' 表示。


示例 1：
输入：board =
[["5","3",".",".","7",".",".",".","."]
,["6",".",".","1","9","5",".",".","."]
,[".","9","8",".",".",".",".","6","."]
,["8",".",".",".","6",".",".",".","3"]
,["4",".",".","8",".","3",".",".","1"]
,["7",".",".",".","2",".",".",".","6"]
,[".","6",".",".",".",".","2","8","."]
,[".",".",".","4","1","9",".",".","5"]
,[".",".",".",".","8",".",".","7","9"]]
输出：true

示例 2：
输入：board =
[["8","3",".",".","7",".",".",".","."]
,["6",".",".","1","9","5",".",".","."]
,[".","9","8",".",".",".",".","6","."]
,["8",".",".",".","6",".",".",".","3"]
,["4",".",".","8",".","3",".",".","1"]
,["7",".",".",".","2",".",".",".","6"]
,[".","6",".",".",".",".","2","8","."]
,[".",".",".","4","1","9",".",".","5"]
,[".",".",".",".","8",".",".","7","9"]]
输出：false
解释：除了第一行的第一个数字从 5 改为 8 以外，空格内其他数字均与 示例1 相同。 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。
 */
public class You_xiao_de_shu_du {

    public static void main(String[] args) {
        int index = '3' - '0';
        System.out.println(index);

        // char[][] board = {
        //         {'5','3','.','.','7','.','.','.','.'},
        //         {'6','.','.','1','9','5','.','.','.'},
        //         {'.','9','8','.','.','.','.','6','.'},
        //         {'8','.','.','.','6','.','.','.','3'},
        //         {'4','.','.','8','.','3','.','.','1'},
        //         {'7','.','.','.','2','.','.','.','6'},
        //         {'.','6','.','.','.','.','2','8','.'},
        //         {'.','.','.','4','1','9','.','.','5'},
        //         {'.','.','.','.','8','.','.','7','9'}};
        // System.out.println(isValidSudoku(board));

    }

    public static boolean isValidSudoku(char[][] board) {
        // 每一行是否有相同的
        Set<Character> lineSet = new HashSet<>();
        // 每一列是否有相同的
        Set<Character> columnSet = new HashSet<>();

        for (int i = 0; i < board.length; i++) {
            char[] chars = board[i];
            lineSet = new HashSet<>();
            for (int j = 0; j < chars.length; j++) {
                char aChar = chars[j];
                if ('.' == aChar) {
                    continue;
                }
                if (lineSet.contains(aChar)) {
                    return false;
                }
                lineSet.add(aChar);
            }

            columnSet = new HashSet<>();
            for (int j = 0; j < board.length; j++) {
                char column = board[j][i];
                if ('.' ==  column) {
                    continue;
                }
                if (columnSet.contains(column)) {
                    return false;
                }
                columnSet.add(column);
            }
        }

        return true;
    }

    public boolean isValidSudoku2(char[][] board) {
        int[][] rows = new int[9][9];
        int[][] columns = new int[9][9];
        int[][][] subboxes = new int[3][3][9];
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char c = board[i][j];
                if (c != '.') {
                    int index = c - '0' - 1;
                    rows[i][index]++;
                    columns[j][index]++;
                    subboxes[i / 3][j / 3][index]++;
                    if (rows[i][index] > 1 || columns[j][index] > 1 || subboxes[i / 3][j / 3][index] > 1) {
                        return false;
                    }
                }
            }
        }
        return true;
    }

    public boolean isValidSudoku3(char[][] board) {
        int[][] rows = new int[9][9];
        int[][] column = new int[9][9];
        int[][][] subboxes = new int[3][3][9];
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char achar = board[i][j];
                if (achar != '.') {
                    int index = achar - '0' - 1;
                    rows[i][index]++;
                    column[j][index]++;
                    subboxes[i/3][j/3][index]++;
                    if (rows[i][index] > 1 || column[j][index] > 1 || subboxes[i/3][j/3][index] > 1) {
                        return false;
                    }
                }
            }
        }
        return true;
    }
}
